1. Field of the Invention
The present invention relates to a semiconductor manufacturing system, and more particularly, to a vacuum leakage detecting device for detecting vacuum leaks in the manufacturing system.
A claim of priority is made under 35 U.S.C. §119 for Korean Patent Application 2003-72868, filed on Oct. 20, 2003, the contents of which are hereby incorporated in its entirety by reference.
2. Description of the Related Art
A semiconductor device is generally fabricated by selectively and repetitively performing photolithography, etching, diffusion, chemical vapor deposition, ion implantation, and metal deposition processes on a wafer. The manufacturing processes are performed by supplying process gases into the interior of a closed process chamber to react the gases with a wafer placed within the process chamber. This semiconductor fabrication process is usually conducted under a vacuum state, and where the vacuum state is accurately maintained in the process chamber, the fabrication process is more efficient.
Most semiconductor manufacturing systems are provided with a vacuum leakage sensing device to detect vacuum leakages. However, even if the vacuum sensing device detects a vacuum leakage, it is difficult to accurately determine the exact source of the vacuum leakage. In order to determine the specific source of the leakage, an operator must disassemble and check each individual component.
FIG. 1 illustrates a conventional semiconductor manufacturing system capable of detecting vacuum leakages.
The semiconductor manufacturing system has the following configuration. Process chamber 10 is provided that is capable of performing various manufacturing processes, such as deposition, plasma, diffusion, chemical vapor deposition processes, etc.
Gas supply line 24 is connected to an upper portion of process chamber 10. Air valve 26 is installed on gas supply line 24 to control the flow of gas to process chamber 10.
Mass flow controller (MFC) 28 is connected to gas supply line 24 to regulate the flow of gas through air valve 26 into process chamber 10.
Shower heads 14 are installed in process chamber 10 and connected to supply pipe 24, to evenly distribute gas within the interior of process chamber 10.
Heater 16 is installed in a lower portion of process chamber 10, to heat wafers (not shown).
Pump line 18 is connected to the lower portion of process chamber 10 at one end and connected to dry pump 22 at the other end. Pump line 18 is used to exhaust any residual gas from process chamber 10.
Fluid isolation valve 20 is installed on pump line 18 to isolate process chamber 10 and dry pump 22.
The conventional semiconductor manufacturing system supplies gas from gas supply line 24 and heat from heater 16. Also, a controller (not shown) operates dry pump 22 to remove unnecessary residual gas through pump line 18 from process chamber 10 to form a vacuum.
However, if a malfunction occurs in the conventional semiconductor manufacturing system while in operation or a predetermined number of uses have occurred, each one of the constituent parts must be disassembled from the process chamber 10 to be cleaned and then reassembled. After reassembling the constituent parts, an automatic leak detection program is run to check for proper sealage (i.e., lack of leakage). The automatic leak detection program closes fluid valve 20 and opens air valve 26, and then detects whether there is a gas leakage at one or more of several potential external leak points P1 through P9 within process chamber 10.
The conventional semiconductor manufacturing system can detect whether there is a gas leakage at one or more of the potential external leak points P1 through P9, but it may fail to detect a gas leak in the pump line 18 caused by the deterioration of an O-ring (not shown) in fluid valve 20.
Furthermore, when the externally exhausted gas is ventilated through pump line 18, a reaction between SiH4 gas and air often will cause a powdery residue to form in the pump line 18. The resulting loss in vacuum pressure causes a process defect, such as voids in a metal layer being deposited on a substrate in the process chamber 10, to occur.
Accordingly, it is desirable to provide a vacuum leakage detecting device for use in a semiconductor manufacturing system, which is capable of detecting gas leakage at several external and internal leak points. It is further desirable to provide a vacuum leakage detecting device capable preventing the formation of metal voids.